Are small amounts of soap or detergent harmful to the growth of plants?
- Radish or beet seeds
- Soap and detergent
- 3 Styrofoam cups
- 2 Quart jars
Do this first:
Fill the jars to the same levels with water, and then make soap and detergent solutions. For one jar use 1/4 teaspoon detergent and fill with water. For the other, use 1/4 teaspoon soap and fill with water.
1.Plant 2 seeds in each cup, about 1-cm deep, and place in a sunny windowsill.
2. Water one cup with 2 tablespoons of soap solution every day.
3. Water a second cup with 2 tablespoons of detergent solution every day.
4. Water the remaining cup with 2 tablespoons of tap water every day.
5. Chart the growth of plants in each cup. Compare the results. Which sprouts first? Which grows fastest?
OTHER IDEAS TO EXPLORE:
What happens to soap when it leaves your bathtub?